Dopamine Agonists Exert Nurr1-inducing Effect in Peripheral Blood Mononuclear Cells of Patients with Parkinson's Disease / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Nurr1 plays an essential role in the development, survival, and function maintenance of midbrain dopaminergic (DA) neurons, and it is a potential target for Parkinson's disease (PD). Nurr1 mRNA can be detected in peripheral blood mononuclear cells (PBMCs), but whether there is any association of altered Nurr1 expression in PBMC with the disease and DA drug treatments remains elusive. This study aimed to measure the Nurr1 mRNA level in PBMC and evaluate the effect of Nurr1 expression by DA agents in vivo and in vitro.</p><p><b>METHODS</b>The mRNA levels of Nurr1 in PBMC of four subgroups of 362 PD patients and 193 healthy controls (HCs) using real-time polymerase chain reaction were measured. The nonparametric Mann-Whitney U-test and Kruskal-Wallis test were performed to evaluate the differences between PD and HC, as well as the subgroups of PD. Multivariate linear regression analysis was used to evaluate the independent association of Nurr1 expression with Hoehn and Yahr scale, age, and drug treatments. Besides, the Nurr1 expression in cultured PBMC was measured to determine whether DA agonist pramipexole affects its mRNA level.</p><p><b>RESULTS</b>The relative Nurr1 mRNA levels in DA agonists treated subgroup were significant higher than those in recent-onset cases without any anti-PD treatments (de novo) (P < 0.001) and HC groups (P < 0.010), respectively. Furthermore, the increase in Nurr1 mRNA expression was seen in DA agonist and L-dopa group. Multivariate linear regression showed DA agonists, L-dopa, and DA agonists were independent predictors correlated with Nurr1 mRNA expression level in PBMC. In vitro, in the cultured PBMC treated with 10 μmol/L pramipexole, the Nurr1 mRNA levels were significantly increased by 99.61%, 71.75%, 73.16% in 2, 4, and 8 h, respectively (P < 0.001).</p><p><b>CONCLUSIONS</b>DA agonists can induce Nurr1 expression in PBMC, and such effect may contribute to DA agonists-mediated neuroprotection on DA neurons.</p>

Effect of Bushen Huoxue Decoction on the orphan receptor and tyrosine hydroxylase in the brain of rats with Parkinson's disease / 中国结合医学杂志

<p><b>OBJECTIVE</b>To explore the effect of Bushen Huoxue Decoction (BHD) on the orphan receptor (Nurr1) and tyrosine hydroxylase (TH) in the brain of rats with Parkinson's disease (PD).</p><p><b>METHODS</b>One hundred and twenty SD rats were divided into 100 in the model group and 20 in the normal control group, fifty-eight SD rats from the model group, established into PD model successfully by injuring their substantia nigra (SSN) with 6-hydroxydopamine, were divided equally into the model group and the test group, and they were treated with saline and BHD, respectively, for eight successive weeks. The change in the rats' behavior before and after treatment was observed by counting the cycles of rotation induced by apomorphine injection; the pathology of neurons, level of Nurr1 mRNA expression, and amount of TH positive cells in SSN were observed after treatment.</p><p><b>RESULTS</b>The rats' behavior was improved in the tested group significantly, the rotation cycle after treatment being 84.0 ± 20.0 cycles/40 min, which was significantly lower than that in the model group (377.0 ± 62.3 cycles/40 min, P<0.01). Besides, the Nurr1 mRNA expression and TH positive cell in the test group were 0.97 ± 0.15 and 49.40 ± 14.72, respectively, which were significantly higher than those in the model group, 0.22 ± 0.03 and 5.45 ± 2.58, respectively (all P<0.01).</p><p><b>CONCLUSION</b>BHD could treat PD by enhancing the Nurr1 mRNA expression, increasing the TH content in brain, and promoting the repairing of injured neuron in cerebral SSN.</p>

Association of the polymorphisms in NURR1 gene with Parkinson's disease / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the association between the polymorphisms of [c.-2922(C)2-3 and IVS6+ 18insG] in the NURR1 gene and Parkinson's disease (PD) in a Han population from Sichuan province.</p><p><b>METHODS</b>PCR, allele-specific PCR (AS-PCR) and restriction fragment length polymorphism (RFLP) were used to determine the genotype of each subject.</p><p><b>RESULTS</b>The two polymorphic sites in 241 PD patients and 236 controls with matched age, gender and ethnicity were analyzed. In the IVS6+ 18insG site, the difference of genotype frequencies of 3G/3G, 3G/2G and 2G/2G was not statistically significant. However, the 3G/2G genotype frequency was significantly higher in the PD with age of onset being < 50 years than that in controls (chi (2)= 6.537, P= 0.011; OR= 1.913, 95%CI: 1.159-3.158). No significant differences were found in allele and genotype frequencies of the c.-2922(C)2-3 site in the promoter region between the PD and controls (P= 0.766).</p><p><b>CONCLUSION</b>This study suggested that the IVS6+ 18insG polymorphism may be associated with genetic susceptibility of PD with age of onset being < 50 years and the c.-2922(C)2-3 site in the promoter region may not be a risk factor for PD in authors' patient group.</p>

Effects of Nurr1 down-regulation on the expression of tyrosine hydroxylase and neurite extension in dopaminergic cells / 生理学报

In the experiment, we designed and synthesized two siRNAs based on the sequence of nuclear receptor-related factor 1 (Nurr1) mRNA. They were separately subcloned into the plasmid of pSilenCircle (pSC) containing U6 promoter. The pSC-Nurr1 vectors (pSC-N1 and pSC-N2) specific to Nurr1 gene and the negative control vector of short-hairpin RNA (shRNA) eukaryotic expression vector were constructed. We cultured the dopaminergic cell line MN9D and the verified vectors were transfected with LipofectamineTM 2000 in vitro. The positive cell clones transfected with pSC were obtained after being screened with 500 mug/ml G418. After that, the silencing effects of Nurr1 and TH mRNA or protein were detected by real time RT-PCR and Western blot. The neurite extension of MN9D cells was observed and photographed by inverted microscope. The results showed that Nurr1 mRNA expression in MN9D cells was specifically down-regulated by the vectors of pSC-N1 and pSC-N2, and the silencing effects were 62.3% and 45.6%, respectively. The dopaminergic phenotype of TH mRNA was also suppressed significantly and the silencing effects were 76.3% and 62.6%, respectively. Meanwhile, the expressions of Nurr1 and TH proteins were also significantly suppressed, and the silencing effects of Nurr1 and TH protein were 57.4%, 72.0% and 79.1%, 70.1% respectively. The negative control and liposome groups had no effect on the two genes. In conclusion, Nurr1 shRNA expressing vectors can inhibit the expressions of Nurr1 and TH mRNA or protein in MN9D cells, and Nurr1 might play a role in neurite extension of MN9D cells. Nurr1 shRNA expressing vector may provide a novel applicable strategy for the study on the function of the genes associated with Parkinson disease and the development of dopaminergic neuron.

Novel splicing variant of the human orphan nuclear receptor Nurr1 gene / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Nurr1 is a member of the nuclear receptor superfamily of transcription factors. The objective of the present study was to identify novel splicing variants of the gene in neuronal and non-neuronal tissues and determine their functions.</p><p><b>METHODS</b>Reverse transcription-polymerase chain reaction (RT-PCR) analysis was used to screen for Nurr1 splice variants in the adult human central nervous system (CNS) and in other tissues such as lymphocytes, and liver, muscle, and kidney cells. Functional assays of the variants were performed by measuring Nurr1 response element (NuRE) transcriptional activity in vitro.</p><p><b>RESULTS</b>In this study, the authors identified a novel splicing variant of Nurr1 within exon 5, found in multiple adult human tissues, including lymphocytes, and liver, muscle, and kidney cells, but not in the brain or spinal cord. Sequencing analysis showed the variant has a 75 bp deletion between nucleotides 1402 and 1476. A functional assay of the Nurr1-c splicing variant, performed by measuring NuRE transcriptional activity in vitro, detected a 39% lower level of luciferase (LUC) activity (P < 0.05).</p><p><b>CONCLUSION</b>A novel splicing variant of Nurr1 exists in human non-neuronal tissues and functional assays suggest that the variant may act as an alternate transcription regulator.</p>